I want to submit someruns but dont know how to calculate how long they were

just add up all the ingame times of the levels ig?

There’s a timing tool in the resources tab. It’s an Excel spreadsheet, which comes with a guide by B.G.B. on how to use it. I’ll link it here for convenience: https://www.speedrun.com/ultrakill/resources/ij9lr

If you can’t use Excel for whatever reason, you can use this instead and it works fine:

https://www.grun1.com/utils/timeCalc.html